Shareholders’ Equity (Stock Option and Restricted Stock Award Activity) (Details)	12 Months Ended
	Dec. 31, 2019 USD ($) $ / shares shares
Equity Awards
Outstanding beginning balance, Shares underlying stock options and restricted stock awards (in shares) | shares	6,466,214
Granted, Shares underlying stock options and restricted stock awards (in shares) | shares	2,126,023
Exercised, Shares underlying stock options and restricted stock awards (in shares) | shares	(5,211)
Forfeited, Shares underlying stock options and restricted stock awards (in shares) | shares	(2,970,186)
Outstanding ending balance, Shares underlying stock options and restricted stock awards (in shares) | shares	5,616,840
Exercisable ending balance, Shares underlying stock options (in shares) | shares	3,645,726
Weighted- average Exercise Price per Share
Outstanding beginning balance, Weighted - average exercise price (in dollars per share) | $ / shares	$ 23.26
Granted, Weighted - average exercise price (in dollars per share) | $ / shares	6.33
Exercised, Weighted - average exercise price (in dollars per share) | $ / shares	6.00
Forfeited, Weighted - average exercise price (in dollars per share) | $ / shares	18.29
Outstanding ending balance, Weighted - average exercise price (in dollars per share) | $ / shares	19.50
Exercisable ending balance, Weighted - average exercise price (in dollars per share) | $ / shares	$ 22.76
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Outstanding ending balance, Weighted - average remaining contractual term (yrs)	4 years 4 months
Exercisable ending balance, Weighted - average remaining contractual term (yrs)	4 years 5 months 22 days
Exercisable ending balance, Aggregate intrinsic value | $	$ 0